package com.itelite.common.util;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletResponse;
import javax.validation.constraints.NotNull;
import java.io.IOException;

@Component
public class SpringUtils implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(@NotNull ApplicationContext applicationContext) throws BeansException {
        if(SpringUtils.applicationContext == null) {
            SpringUtils.applicationContext = applicationContext;
        }
    }

    //获取applicationContext
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    //通过name获取 Bean.
    public static Object getBean(String name){
        return getApplicationContext().getBean(name);
    }

    //通过class获取Bean.
    public static <T> T getBean(Class<T> clazz){
        return getApplicationContext().getBean(clazz);
    }

    //通过name,以及Clazz返回指定的Bean
    public static <T> T getBean(String name,Class<T> clazz){
        return getApplicationContext().getBean(name, clazz);
    }
    public static void makeResponse(HttpServletResponse response,Object result) throws IOException {
        response.setContentType("application/json;charset=UTF-8");
        response.getWriter().write(new ObjectMapper().writeValueAsString(result));
    }

}